Air brake



Patented Feb. 24, 1942 .JiA-IRBRAIQJE.. 1 Charles A. Campbe l, Watertown,

YL, as signor to The New,.York'Air Brake Company, a .corporation of New Jersey ,ApplicationJune 2 1, 1940, Serial No. 341,772 I 2 Claims. (01. 3025 -13 l This invention relates to air brakesandpar- I ticu'larly to engineers brake valves, such for examp'le'as the well known 1-1-6 valve. These'and other similar valves are equipped with a latch sector-having motion limiting stop shouldersat opposite ends of the sector and impositivedetents at appropriate points :between the ends of 1 the sector. Thousands of these valves are in use and it is impossible toredesign the sectors.

- Efiforts have been made to use a latch having a roller nose which cooperates with the-sector. This permits freer action, but roller latches heretofore used have been discarded because the pintle on which the roller is mounted soon becomes bent. I have discovered that this is caused by collision of the roller with the limiting stop shoulders of the sector, and has nothing to do with the ordinary detent action of the roller.

Another disadvantage of prior art latches was that the latch nose was eccentric with reference to the guide in which the latch nose was mounted. This caused cramping and is avoided in the new latch.

The present invention produces a new handle with a new type of latch having a roller nose. The latch head and the nose areso coordinated in form and dimension that the roller exclusively coacts with the impositive detents on the sector, and the latch head so shrouds the roller that the latch head itself engages the end stops of the sector and prevents engagement of the roller therewith. Consequently the pintle for the roller is never over-stressed and a successful roller latch nose isma'de available for the first time.

The preferred embodiment of the invention will now be described by reference to the accompany ing drawing, in which: Figure 1 is a plan view of an engineers brake valve handle and latch sector with the handle in full release position, that is with the latch head against one of the end limiting stops. The running position of the handle, in which the roller on'the latch head engages one of the impositive detent notches, is shown in dotted. lines.

Fig. 2 is an enlarged fragmentary'viewof a I portion of Fig. 1 indicating somewhat more clearlyhow the selective engagement above mentioned is secured.

Fig. 3 is a vertical axial section through the Fig. 5 isan elevation showing the preventer stop mounted on the handle. I

- circles the key [4 the handle is offset downward I3 beneath the offset l1.

Referring firstto Figs. 1, 2 and 3, the upper cap of the engineers brake valve is'indicated at 6 and, as usual, is formed on its periphery with a latch sector having end shoulders I and 8. The shoulder l defines full release position and the shoulder 8 defines emergency position. The notch 9 defines running position, notch l I defines holding position, and the left and theright ends respectively of the elongated notch 12 define lap and service positions. These sectors are standardized and are in extensive use. It is impracticable to change the design.

The problem solved by the present application is the provision for use with standard sectors of a roller type latch which will preserve its full operative characteristics regardless of rough usage.

The handle i3 is attached to the key M by nuts I5. The key 14 turns the-well known rotary valve (not shown) forming part of the engineers brake valve. From the hub I6 which enas indicated at I! and is there of channel form. Outward from the oiTset, the handle assumes the generally slightly tapered form of circular cross-section, clearly indicated in the drawing.

Mounted in a bore I8 in the handle and urged radially inward by a coil compression spring 19 is aplunger 2| which is formed integrally with a flat latch head 22. The latch head 22 fits snugly in the radial elongated guiding slot 23 in handle The head 22 is retained by pin 24 which is fixed in the handle and passes through a larger drilled hole 25 in the head 22. Latch head 22 is directly opposite to the latch sector and the stem 2| is very nearly centered thereon. The forward end of the latch nose 22 is beveled, as indicated at 26, and a cross slot is milled therein to receive the roller 21 mounted on a pintle 28 which is fixed in place in the head 22.

The diameter of the roller is less than the transverse dimension of the head 22 (see Fig. 2), so that the roller is exposed at the top but shrouded at the sides. Thus when the handle is moved to full release position (Fig. 1), or to emergency position (in which the head22 engages the shoulder 8), the roller 21 is not subjected to impact.

In all intermediate positions, including engagement with the notches 9, II and I2, the roller 2! and not the latch head 22 engages the sector. Since the engagement with the notches 9, II and I2 is of an impositive character and imparts little shock, no damage is done to the pintle 28 on which the roller 21 is mounted.

It has heretofore been proposed to mount removably on brake valve handles an auxiliary stop or preventer which is used when it is desired to prevent the engine driver from using full release position. The present invention permits the use of such a stop and for that purpose the handle adjacent the ofiset I1 is provided with two upstanding transverse ribs 3| and 32 and is cross-drilled, as indicated at 33. 77

The preventer stop 34 with the U-shaped attaching bracket 35 is mounted between the flanges 3| and 32 and held by a bolt 36, the mode of mounting being clearly indicated in Figs. 4 and 5. It will be observed that this preventer is attached at a point wholly above 1. The combination of an engineers brake valve body provided with a latch sector having terminal stops defining release and emergency positions and having an intermediate portion formed with impositive detent notches; a brake valve handle pivoted on said body concentrically with said latch sector; a latch head opposed to said sector; latch-head guides in said handle confining said head to radial motion toward and from said sector; a spring urging said head toward said sector; and a roller journaled and partially housed in said latch head, the arrangement being such that the head alone engages said limit stops and-the roller alone engages intermediate portions of said sector including said detent notches.

2. The combination of an engineers brake valve body provided with a latch sector having inclined impositive latching shoulders, and at least one terminal stop shoulder of greater radial depth than said latching shoulders; a brake 

